The flow-through boiler
An electric instantaneous water heater for hot water preparation has advantages over a conventional (kitchen) boiler. A flow-through boiler does not suffer from waiting times as with a combi central heating boiler or from downtime losses as with a conventional boiler. Moreover, there is no inlet combination and therefore no need to connect to a drain. Since the product only needs to heat water when in use, comfort is higher and energy consumption lower.
The "idle loss" - is the loss of heat that the water heater loses at rest before the water has to be reheated. For a typical 10-liter kitchen water heater, this can quickly add up to 40W/h - 345kWh per year.
Comfort
The disadvantage, however, is the electrical connection in the home that must be suitable for the short-term high power consumption of these appliances. Another disadvantage is a limited tap water flow rate compared to the high electrical connection value of the appliance. To give an example; to shower in terms of comfort (tap flow rate) comparable to a CW4 central heating appliance on an electrically heated appliance soon requires 18kW of electrical power. For a CW5 comparable comfort 27kW! In addition to a 3x50A electrical grid connection, many residential distribution boards (distribution board) are not designed for these currents and should be modified where possible. The costs in this case do not outweigh the benefits. A boiler (vessel) with a capacity of, for example, 80-120ltr is a much better and cheaper solution in these cases.
The electric central heating boiler: A modern approach to heating.
In the Netherlands, the majority of homes still use central heating. Central heating with a delivery system often consisting of radiators or floor heating through which water flows. The traditional central heating boiler, which burns natural gas, is typically used to heat this water. An electric central heating boiler, on the other hand, also operates with water in radiators, but does not use natural gas. Instead, the water is heated by one or more electric heating element(s).
Electric (Main) Heating
Is not the most efficient way of heating. However, for small rooms and areas it can be a solution. It must be ensured that electric heating does not overload the electrical system. Electric heating does not have the best efficiency and only becomes interesting when you already have a solar system with a surplus of electricity. This is especially true when the net-metering scheme is abolished. We are happy to investigate the possibilities for you and give advice where necessary.
Saving on energy costs with an electric central heating boiler?
A comparison between an electric central heating boiler or electric underfloor heating and a natural gas boiler currently shows that electric heating is not more economical. In fact, the energy cost of heating an average home with an electric central heating boiler is significantly higher than with a natural gas boiler. In terms of energy efficiency, it boils down to the fact that 1 m3 of gas provides about the same amount of energy as 9 kWh of electricity with an electric boiler.
Calculation example.
The cost of 1 m3 of gas is around €1.40 while the cost of 9 kWh of electricity is about €3.42. So if you choose to heat your home entirely with an electric central heating boiler, you will spend almost two and a half times as much compared to a natural gas boiler. *prices jan2024
Although solar panels can generate some of the electricity needed, their efficiency is limited. After all, heat demand is highest in the winter period but yield of electricity from solar panels is lowest. As long as the net-metering scheme exists, using self-generated electricity for electric heating is not profitable. However, if the net-metering scheme disappears, using self-generated electricity for heating may make sense
Is my home suitable for an electric central heating boiler?
Not every home is suitable for an electric central heating boiler. Most homes have a main electrical connection with a 1×35 or 1×40 amp fuse. An electric central heating boiler that needs to heat an entire house requires a three-phase connection with a fuse of at least 3×25 Amps but usually 3×35 Amps. This connection must be requested from the grid operator and incurs additional costs.
Electric Heating: Not Always a Good Idea.
An electric central heating boiler for the complete heating of a house is often not only more expensive to operate, but also often not legally allowed due to the tightened building code. Nevertheless, (partial) electric heating is not always a bad choice. In situations where certain rooms are used only sporadically, electric heating can be efficient and comfortable, despite not being considered a serious alternative to a natural gas HR boiler.
Electric heating and the Building Code
Section 2 of the Housing Act states that rules on the safety, health, usability, energy efficiency and environmental impact of buildings shall be laid down by order in council. Those rules are laid down in the 2012 Building Code. All buildings in the Netherlands must comply with these rules. New construction, but also existing.
Since Jan. 1, 2021, the Netherlands has been using a new calculation method to determine the energy performance of buildings. The new determination method is called NTA 8800. The energy performance of a building, calculated with NTA 8800, must comply with the European Energy Performance of Buildings Directive (EPBD).
The new method replaces a number of existing methods for new construction and existing buildings, namely NEN 7120, Nader Voorschrift and ISSO 75.3. NTA 8800 follows European standards and replaces the current EPC and EI indicators with the energy requirement per square meter per year (kWh/m².yr).
Building Code Article 6.55a states that a home's heating system must not use more than 1.31 kWh of energy to generate 1 kWh of heat. The electric central heating boiler usually does not meet this requirement and is therefore usually not allowed.
New construction: nearly energy-neutral (BENG)
For all new construction, both residential and non-residential, permit applications from Jan. 1, 2021, must meet the requirements for nearly zero energy buildings (BENG). The requirements set a maximum value for energy demand, primary fossil energy use and a minimum value for the share of renewable energy. These three requirements are determined based on the NTA 8800. BENG stems from the Energy Agreement for Sustainable Growth and from the European Energy Performance of Buildings Directive (EPBD). An introductory video on BENG can be found and downloaded at: www.rvo.nl/BENG.
As of January 2024, the Building Decree has been replaced by the Building Works Environment Decree (Bbl). The Bbl is the new guideline for construction: it contains requirements that buildings must meet in order to guarantee the necessary quality and safety.
More information on this topic can be found on the central government website.
https://www.rvo.nl/onderwerpen/wetten-en-regels-gebouwen/energieprestatie-eisen-verbouw-renovatie